Jonathan Siah, 8, and his sisters Angeline, 12, and Elizabeth, 7, turn the carpark outside their apartment into a playground each evening. Photo / Greg Bowker

Health researchers lamenting physical inactivity among Auckland's pre-teens - most of whom rely on their parents to drive them about - want developers of a "compact city" to reserve more playing spaces for children.

A study of 253 children aged 9 to 12 by researchers from three universities found them more involved in sedentary pastimes such as indoor computer games than in physical pursuits.

And when they left home they were more likely to be driven in cars by their parents than to go on foot or by bike or scooter.

Friends' homes or local dairies were the only destinations to which they made more than half their trips without adult supervision.

Parents or caregivers accompanied them on 59 per cent of trips to and from school, 77 per cent of shopping excursions and 92 per cent of travel to organised sports.

The children in the study kept trip diaries and wore GPS tracking monitors and accelerometers so the researchers could analyse their movements over seven days.

Only those from low socio-economic southern and eastern suburbs showed any great independence.

Karen Witten, the Massey University professor who led the study, said it followed a Transport Ministry finding that the average time children spent on "active travel" such as walking and cycling had shrunk from 130 to 72 minutes a week in the 20 years to 2012.

The proportion who usually travelled to school by car rose from 31 per cent to 58 per cent.

Professor Witten said parents discouraging youngsters from walking or biking to school because of perceived dangers created a "social trap where the children who remain on the street are less safe because there are fewer other children on the street".

For many children, outdoor play and movement had become activities dependent on the supervision of adults, and the concept of adventure was something found in a computer game. 'That makes what we call the threshold spaces - spaces closer to home - really important as play spaces for children," Professor Witten said. "We think it's important in all residential development that there is communal indoor and outdoor space that provides opportunities for children."

She said planners need look no further than the Freemans Park development of the 1960s for a positive example of how to provide child-friendly medium-density housing which had "lots of space between the apartments".

Auckland Council has a new strategic action plan to guide growth of the parks and open-space network over the next decade. additional reporting:

Finding your space to roam

Veronika Alimuddin's children Angeline, Jonathan and Elizabeth Siah take their leisure where they find it, turning a carpark into a playground after office workers leave for the night.

The Newmarket trio - aged 12, 8 and 7 - persuaded the landlord of their four-storey office and apartment block to let them use an outside shed for their bikes and balls, which they bring out once the carpark empties.

Sometimes their mother takes them to Auckland Domain or a school playground.

As well as being among 253 Auckland children whose activities were surveyed in a multi-university study, Angeline was one of a small group chosen to develop its own research question to investigate how its peers found central-city living.

She has recommended to planners that owners of other apartment blocks be asked to follow her landlord's example by providing storage sheds for children's play.

Angeline admits to spending about 60 per cent of her spare time on sedentary activities, like most others surveyed. However, she appreciates the health benefits of outdoor exercise and enjoys waterfights and tennis with her brother and sister. She is critical of a lack of parks suitable for children's play in the inner city.

"Victoria Park is too close to the motorway and Albert Park is more for relaxing, not really a play area."

Her mother encourages the children to be active within the constraints of an urban environment but is reluctant to let them walk far by themselves.

Getting about

Trips made independently by children, without adults:

• To sports: 8%• To shopping centres: 23%• To school: 41%• To the dairy: 56%• To friends' homes: 60%